opengl es - Vertex normals for a cube -


a cube has 8 unique vertices. true each of these 8 vertex normals (unit vectors) making 135 degree angle each of edges shares vertex? , vertex normal pointing outward/out of cube? answer should technically correct. or depends on how cube defined (drawn) using triangle strips or indices define 2 triangles each side of cube? purpose of vertex normal smooth shading , lighting in opengl es application.

if cube defined 8 unique vertices, normals making 135 degree angle each edge, mentioned.

however, cube defined using 24 vertices reason. allows have vertex normals perpendicular each face, "duplicating" vertices @ each corner. defining cube way is, effectively, defining 6 individual faces, each pointing outwards appropriately.


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